Originally Posted by
pdfbt40
If that was true then you wouldn't be able to easily swap a ST170 head onto a 'blacktop' engine.
The detail of the valves, cams, etc. are different as it has high lift cams and, as mentioned, the VVT on the inlet cam. The inlet port is bigger and flows a lot better than the shape of the standard/RS head, but the valve sizes (but not stem lengths), angles, cam centre lines, etc, etc. are the same as the standard/RS blacktop.
Oh, and even the head chamber volume is the same......
Martin
Okay, to clarify my comment to fight off the pedants.. I was referring to the flow characteristics of the head as that is what is important in head related discussions.. I think you'll find the inlet valves are a different size too.. Try putting both heads side by side and doing a proper comparison
